Photovoltaic farms are a key element of the transition to sustainable energy; however, their efficiency and power stability require advanced technological solutions. The project involving the implementation of a control system for active reactive power compensation, circuit breaker condition monitoring, and remote low-voltage side management, carried out by ANIRO, is an example of innovative solutions in the field of energy management and reactive power compensation in photovoltaic farms. The following case study presents the main challenges, applied technologies, and the benefits achieved through the implementation of the system.
Project Description
The photovoltaic farm was connected to an industrial facility via two 15 kV medium-voltage cables exceeding 1 km in length. The farm generates energy with a maximum output of 2 × 7.5 MW, which is transmitted directly to the facility for on-site consumption. Due to the nature of the installation and the requirements for efficient power management, the implemented system was designed to provide reactive power compensation and maintain an appropriate power factor, as well as enable circuit breaker condition monitoring and remote control capabilities.
Technical Challenges
- Large-scale reactive power management
Energy generated by the photovoltaic farm often introduces excess reactive power, which can reduce the efficiency of the entire power supply system. To control this, an active compensation system was designed to respond dynamically to load changes on both the photovoltaic farm side and the industrial facility side.
- Long-distance power transmission
Due to the long distance (over 1 km) between the farm and the facility, the project required a stable communication system enabling efficient real-time monitoring and control of electrical parameters.
- Maintaining active and reactive power parameters
A high power factor is crucial for ensuring grid stability. The system was designed to prevent the tg φ coefficient from exceeding permissible values in both capacitive and inductive load directions in order to avoid additional costs and improve energy efficiency.
Implemented Solutions
- SVG active reactive power compensation
To compensate reactive power, four 110 kvar active compensators were installed on each medium-voltage line, providing a total of 880 kvar per line. The compensators operate directly at 800 VAC (without the need for an additional matching transformer) and are connected via RS-485 communication to a central LS Electric PLC controller. The compensators respond dynamically to load changes, ensuring power factor stability and reducing costs associated with the transmission of excess reactive power.
- Advanced control and monitoring system
The PLC controller receives data from e2Tango medium-voltage protection relays installed in the facility switchgear, which measure electrical parameters at the metering point with the Distribution System Operator (DSO). As a result, the system monitors parameters such as voltage, current, and tg φ values in real time. This enables precise reactive power control and adjustment of compensator operation according to current demand.
- Remote communication via fiber optic links
Due to the distance between the photovoltaic farm and the facility, communication between the control system and the facility is carried out through two fiber optic links. This ensures secure and fast data transmission required for real-time energy monitoring and management.
Results and Benefits
Thanks to the implemented solutions, the system delivered a number of operational and economic benefits:
- Improved energy efficiency
The active compensation system enabled the power factor to be maintained at an optimal level, eliminating costs associated with the transmission of excess reactive power. Efficient reactive power management also contributes to extending the lifespan of electrical infrastructure.
- Stability and reliability
Real-time monitoring of electrical parameters ensures stable system operation while minimizing the risk of failures. Rapid response to load changes enables continuous adjustment of operating parameters and maintenance of grid stability.
- Remote management and time savings
Thanks to remote data access and the ability to manage devices via fiber optic communication links, the system enables fast decision-making and diagnostics without requiring physical presence on site.
The completed project involving active reactive power compensation as well as remote monitoring and management of photovoltaic farm parameters is an excellent example of an innovative and advanced approach to renewable energy management. Through the use of active compensators, an advanced PLC controller, and efficient fiber optic communication, it was possible to achieve high energy efficiency, reduce operating costs, and ensure stable system operation. Implementations of this type not only improve the competitiveness of enterprises but also contribute to the development of sustainable energy sources.